| Definition:
Limewash is one of the simplest, but also one of the most effective, external
ìpaintî treatments. It consists of a milk-like mixture of water and lime
used to coat the exterior or interior surfaces of a structure. It has no
added binding medium. Calcium oxide (quicklime) is made up as a slurry
in water, and brushed directly onto the wall. As the water evaporates,
the calcium oxide takes up carbon dioxide from the air and forms insoluble
calcium carbonate. Slaked lime mixed with water will rub off rather easily.
Traditionally, additional ingredients included glue, or size water, to
bind and improve adhesion. Sometimes, common salt or calcium chloride would
be added to tallow washes (Lime-tallow limewash) to assist the tallow to
emulsify, and being hygroscopic would assist the carbonation of the lime
on exposure. It is possible to tint limewash, using chemically inert pigments
such as ochres and umbers, but limewashes are usually white. |
Definizione:
Pellicola di rivestimento tradizionalmente impiegata nella finitura di
superfici intonacate, generalmente costituita da calce idrata o grassello
mescolato con acqua e sostanze coloranti. Al fine di migliorarne l'adesività
e la resistenza alle intemperie possono essere impiegati nella preparazione
della tinteggiatura carbonato di calcio, colla forte, olio cotto, tempera
d'uovo, latte, ecc. |
